Response to the letter to the editor: Lassen et al. 3D PET/CT 82 Rb PET myocardial blood flow quantification: comparison
- PDF / 140,368 Bytes
- 2 Pages / 595.276 x 790.866 pts Page_size
- 74 Downloads / 147 Views
LETTER TO THE EDITOR & REPLY
Response to the letter to the editor: Lassen et al. 3D PET/CT 82Rb PET myocardial blood flow quantification: comparison of half-dose and full-dose protocols Martin Lyngby Lassen 1 & Daniel S. Berman 1 & Piotr Slomka 1
# Springer-Verlag GmbH Germany, part of Springer Nature 2020
Dear Sir, We have received the letter to the editor written by Dr. Renaud et al. [1], addressing our recent publication regarding system saturation with standard 82Rb doses for PET myocardial perfusion imaging [2]. Herein, we address their comments in a point-by-point fashion below. In their letter, the authors note that the injection activities of 82 Rb employed in our manuscript exceed the proposed injected activities as published in the most recent (2018) joint-position statement between the Society of Nuclear Medicine and Molecular Imaging (SNMMI) Cardiovascular Council and American Society of Nuclear Cardiology (ASNC) [3]. This latest statement proposes injections of 1100 MBq (30 mCi) of 82Rb for the assessments of myocardial blood flow (MBF), which are slightly below the injected activities used in our study (1247 ± 196 MBq (33.7 ± 5.3 mCi))—considered as full-dose studies. The scans acquired in our study were performed (February–September 2016) [2] and were obtained before this position statement, using the most recent published guidelines from ASNC/SNMMI and the European Association of Nuclear Medicine/European Society of Cardiology [4, 5] which recommend 1100–1480 MBq (30–40 mCi) for 3D LYSO PET scanners—the scanner type evaluated in our report. Of note, the PET system saturation was observed in 20% (n = 4) of the cases with full-dose scans. In 3 of these 4 cases, the saturation occurred when using injected activities within 11% of 1100 MBq (30 mCi) of injection dose recommended in the latest joint ASNC/SNMMI position statement. Of these 3 This article is part of the Topical Collection on Letter to the Editor * Piotr Slomka [email protected] 1
Department of Imaging (Division of Nuclear Medicine), Medicine, and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
patients, one had an injected activity even lower than the newly suggested dose (injected activity of 1006 MBq (27.2 mCi)). On the other hand, we did not observe any PET system saturation effects in studies employing the half-dose protocol (662 ± 115 MBq (17.9 ± 3.1 mCi), maximum injected activity of 895 MBq (24.2 mCi)). Regarding the method for identification of PET system saturation, our study relied mainly on visual assessments. Although visual assessments are more subjective than objective quantitative criteria, this identification protocol provides an easily implementable assessment. The findings in our study are in alignment with those of Tout et al. [6] (15% saturation rate) and, thus, suggest that even visual identification of PET system saturation is feasible. Nonetheless, we agree that in future studies more automated methods should be explored. In a paper published by some authors of the letter [7], they have
Data Loading...
